figure

titlestr={'-48 h','-24 h','+6 h','+18 h','+24 h','+48 h'}; 
ystr={'light';'dark'};

for ind=1:6
    for mnd=1:2
        
        subplot(2,6,(mnd-1)*6+ind);
        imagesc(GKa{ind,mnd}');colormap gray
        if mnd==1
            title(titlestr{ind});
        end
        if ind==1
            ylabel(ystr{mnd});
        end
        box off
        set(gca,'xtick',[],'ytick',[]);
    end
end
